I still haven't figured out if JP is actually doing backup vocals or not. Looks like he mimes.
Those are pre-recored vocals. I'm okay withy that because
1) They don't even try to hide it
2) They pretty much use them at all live shows whether they are shooting a live album or not
Same here, because Rush does the same exact thing, and it's fine. Why can't it be fine for Dream Theater to do the same thing?
It just doesn't sound live. Except James, obviously, but work has clearly been done there even so. It sounded a bit more live than this in person.
I guess people who follow DT for their mathematical precision will lap it up, though. For me, drop the bloody click. (Perhaps these last two sentences would be better suited in the controversial opinions thread?)
I blame this on not having mics towards the audience. But then, the crowd noise usually bleeds into the vocal mics. But that doesn't help much at all if the Crowd itself just isn't lively, and constantly roaring.
Haha shieet guys you are all too negative. Fatal Tragedy is the nuts and this was just crazy! Petrucci was rocking it hard and the solos was delivered with great energy imo. I got excited watching this! 
I really don't want to be so hard on one of my favorite bands, but I just watched the new live Blind Guardian video and while that was not as good from a sound or visual perspective, it was still more interesting because it actually looked and sounded live. Then youtube started playing other live videos from various bands and I found them all way better in terms of capturing a live concert. Maybe the crowd shouldn't bother me so much, but it really does. I'm all about that live energy and it just feels dead here.
Blind Guardian usually draws livelier crowds though, Their style would just be weird with a sitting audience like this.
In all honesty, The crowds at the Dream Theater shows I've been to have been relatively calm. The crowd is so laid back, that Me being the One who stands, sings along, and headbangs, is considered obnoxious and detrimental to their show experience. I have only seen that type of crowd at shows here where the Audience tends to be more on the older end of the Age Spectrum, and happen to be more older bands. Rush, Kansas, Joe Satriani, Zappa Plays Zappa, Deep Purple, all these bands audiences are exactly the type of audience I see at Dream Theater shows now.
So, it's not the band that is getting old. It's the fans that are getting old, and they aren't really drawing much of a younger crowd. Or rather, the younger crowd, for some reason, are not going to the shows.